The early work of any artist is often startling, and Alexander Calder’s is particularly so. We think of Calder’s sculpture as the epitome of crisp, Modernist forms—sometimes moving gently, as the mobiles and stabiles do. And we think of his paintings as filled with abstracted, biomorphic shapes.

Night and day 1964 is one of Calder’s many sculptures with moving elements, better known as ‘mobiles’, a term coined by Marcel Duchamp (1887-1968) and adopted by Calder to describe all such works.1 The first mobiles to hang from the ceiling (as does Night and day) appeared in about 1934, although relatively few were made until after the 1940s.